Top-Side Cooling for GaN Power Devices via Embedded Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
GaN-based HEMTs generate substantial heat during operation, posing challenges for effective cooling, especially as technology advances towards higher voltages and frequencies, with conventional bottom-side cooling designs experiencing increased thermal resistance.
Innovation Solution
A packaged semiconductor device with a thermally conductive substrate partially embedded in an electrically insulating encapsulant, allowing for top-side cooling with a large heat sink directly mounted on the exposed substrate, eliminating additional thermal resistance and simplifying PCB design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional bottom-side cooling designs are used for GaN-based HEMTs, then the device structure is simple, but thermal resistance increases and heat dissipation performance deteriorates
Solution Approach 1:
The patent inverts the conventional cooling approach by switching from bottom-side cooling to top-side cooling. The exposed outer side of the thermally conductive substrate at the first side of the encapsulant enables direct mounting of heat sinks on top of the package, reversing the traditional cooling direction and achieving lower thermal resistance and improved heat dissipation performance
2Temperature
If top-side cooling with exposed substrate is implemented, then heat dissipation performance improves, but manufacturing complexity increases
Solution Approach 1:
The patent merges the substrate exposure function with the encapsulation structure. The thermally conductive substrate is partially embedded in the encapsulant such that the outer side is exposed, combining the thermal management function with the protective encapsulation, thereby achieving improved heat dissipation without proportionally increasing manufacturing complexity
Solution Approach 2:
The patent utilizes the vertical dimension by exposing the outer side of the substrate at the first side of the encapsulant, creating a new thermal interface dimension. This allows heat sink mounting in the vertical direction rather than requiring complex lateral thermal paths, simplifying the overall thermal management approach
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances heat dissipation performance and cost-effectiveness by directly transferring heat from the GaN-based power semiconductor device to a heat sink, outperforming traditional bottom-side cooling methods.
Implementation Method 1
A thermally conductive substrate is partially embedded in the encapsulant such that an outer side of the substrate is exposed at the first side of the encapsulant
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A packaged semiconductor includes an electrically insulating encapsulant having opposite facing first and second planar sides. A thermally conductive substrate is partially embedded in the encapsulant such that an outer side of the substrate is exposed at the first side of the encapsulant and an inner side of the substrate is contained within the encapsulant. A GaN based power semiconductor device is completely embedded in the encapsulant and includes: a main side having electrically conductive device terminals, and a rear side that faces away from the main side and is mounted on the inner side the substrate. A plurality of electrically conductive leads is partially embedded in the substrate and electrically connected to the device terminals. Vertical portions of the leads extend away from the substrate towards the second side of the encapsulant.